In our continuing studies on iron-sulfur and flavoproteins, the amino acid sequences of the Spirulina maxima ferredoxin, the Azotobacter vinelandii, and the Anacystis nidulans flavodoxins and the azotoferredoxin component of nitrogenase will be determined. The amino acid sequence data is essential for structure-function studies, for the crystal X-ray diffraction structural studies and for obtaining phylogenetic and evolutionary data. To date, we hve already sequenced 14 different iron-sulfur proteins and two different flavodoxins. We will continue to work closely with the crystal X-ray diffraction groups at the Univ. of Washington and the Univ. of Michigan. In addition, the genetic and phylogenetic data of he organisms containing these proteins will be continued. Since iron-sulfur proteins and flavoproteins play such essential roles as redox proteins in key biological processes, such as in steroid hydroxylation, oxidative phosphorylation and other biological oxidations, the knowledge obtained about the structures of these redox proteins will be useful in ellucidating the structure and mechanism of action of similar proteins found in man.